This invention relates to separation of nitrogen in admixture with methane by Pressure Swing Adsorption (PSA) utilizing in a first stage certain crystalline zeolites which selectively adsorb nitrogen and passing the purge from said first stage which is rich in nitrogen but contains a significant quantity of methane to a second stage containing an adsorbent which selectively adsorbs methane. The novel process of this invention results in an integrated process characterized by the fact that a high recovery of both nitrogen and methane is obtained without generating any innocuous purge effluent gas streams.